/************************************************************************
The page cursor

(c) 1994-1996 Innobase Oy

Created 10/4/1994 Heikki Tuuri
*************************************************************************/

#ifndef page0cur_h
#define page0cur_h

#include "univ.i"

#include "page0types.h"
#include "page0page.h"
#include "rem0rec.h"
#include "data0data.h"
#include "mtr0mtr.h"

#define PAGE_CUR_ADAPT

/* Page cursor search modes; the values must be in this order! */

#define PAGE_CUR_G 1
#define PAGE_CUR_GE 2
#define PAGE_CUR_L 3
#define PAGE_CUR_LE 4
/*#define PAGE_CUR_LE_OR_EXTENDS 5*/ /* This is a search mode used in
                                 "column LIKE 'abc%' ORDER BY column DESC";
                                 we have to find strings which are <= 'abc' or
                                 which extend it */
#ifdef UNIV_SEARCH_DEBUG
#define PAGE_CUR_DBG 6 /* As PAGE_CUR_LE, but skips search shortcut */
#endif                 /* UNIV_SEARCH_DEBUG */

#ifdef PAGE_CUR_ADAPT
#ifdef UNIV_SEARCH_PERF_STAT
extern ulint page_cur_short_succ;
#endif /* UNIV_SEARCH_PERF_STAT */
#endif /* PAGE_CUR_ADAPT */

/*************************************************************
Gets pointer to the page frame where the cursor is positioned. */
UNIV_INLINE
page_t *page_cur_get_page(
    /*==============*/
    /* out: page */
    page_cur_t *cur); /* in: page cursor */
/*************************************************************
Gets the record where the cursor is positioned. */
UNIV_INLINE
rec_t *page_cur_get_rec(
    /*=============*/
    /* out: record */
    page_cur_t *cur); /* in: page cursor */
/*************************************************************
Sets the cursor object to point before the first user record
on the page. */
UNIV_INLINE
void page_cur_set_before_first(
    /*======================*/
    page_t *page,     /* in: index page */
    page_cur_t *cur); /* in: cursor */
/*************************************************************
Sets the cursor object to point after the last user record on
the page. */
UNIV_INLINE
void page_cur_set_after_last(
    /*====================*/
    page_t *page,     /* in: index page */
    page_cur_t *cur); /* in: cursor */
/*************************************************************
Returns TRUE if the cursor is before first user record on page. */
UNIV_INLINE
ibool page_cur_is_before_first(
    /*=====================*/
    /* out: TRUE if at start */
    const page_cur_t *cur); /* in: cursor */
/*************************************************************
Returns TRUE if the cursor is after last user record. */
UNIV_INLINE
ibool page_cur_is_after_last(
    /*===================*/
    /* out: TRUE if at end */
    const page_cur_t *cur); /* in: cursor */
/**************************************************************
Positions the cursor on the given record. */
UNIV_INLINE
void page_cur_position(
    /*==============*/
    rec_t *rec,       /* in: record on a page */
    page_cur_t *cur); /* in: page cursor */
/**************************************************************
Invalidates a page cursor by setting the record pointer NULL. */
UNIV_INLINE
void page_cur_invalidate(
    /*================*/
    page_cur_t *cur); /* in: page cursor */
/**************************************************************
Moves the cursor to the next record on page. */
UNIV_INLINE
void page_cur_move_to_next(
    /*==================*/
    page_cur_t *cur); /* in: cursor; must not be after last */
/**************************************************************
Moves the cursor to the previous record on page. */
UNIV_INLINE
void page_cur_move_to_prev(
    /*==================*/
    page_cur_t *cur); /* in: cursor; must not before first */
/***************************************************************
Inserts a record next to page cursor. Returns pointer to inserted record if
succeed, i.e., enough space available, NULL otherwise. The cursor stays at
the same position. */
UNIV_INLINE
rec_t *page_cur_tuple_insert(
    /*==================*/
    /* out: pointer to record if succeed, NULL
    otherwise */
    page_cur_t *cursor,  /* in: a page cursor */
    dtuple_t *tuple,     /* in: pointer to a data tuple */
    dict_index_t *index, /* in: record descriptor */
    mtr_t *mtr);         /* in: mini-transaction handle */
/***************************************************************
Inserts a record next to page cursor. Returns pointer to inserted record if
succeed, i.e., enough space available, NULL otherwise. The cursor stays at
the same position. */
UNIV_INLINE
rec_t *page_cur_rec_insert(
    /*================*/
    /* out: pointer to record if succeed, NULL
    otherwise */
    page_cur_t *cursor,  /* in: a page cursor */
    rec_t *rec,          /* in: record to insert */
    dict_index_t *index, /* in: record descriptor */
    ulint *offsets,      /* in: rec_get_offsets(rec, index) */
    mtr_t *mtr);         /* in: mini-transaction handle */
/***************************************************************
Inserts a record next to page cursor. Returns pointer to inserted record if
succeed, i.e., enough space available, NULL otherwise. The record to be
inserted can be in a data tuple or as a physical record. The other parameter
must then be NULL. The cursor stays at the same position. */

rec_t *page_cur_insert_rec_low(
    /*====================*/
    /* out: pointer to record if succeed, NULL
    otherwise */
    page_cur_t *cursor,  /* in: a page cursor */
    dtuple_t *tuple,     /* in: pointer to a data tuple or NULL */
    dict_index_t *index, /* in: record descriptor */
    rec_t *rec,          /* in: pointer to a physical record or NULL */
    ulint *offsets,      /* in: rec_get_offsets(rec, index) or NULL */
    mtr_t *mtr);         /* in: mini-transaction handle */
/*****************************************************************
Copies records from page to a newly created page, from a given record onward,
including that record. Infimum and supremum records are not copied. */

void page_copy_rec_list_end_to_created_page(
    /*===================================*/
    page_t *new_page,    /* in: index page to copy to */
    page_t *page,        /* in: index page */
    rec_t *rec,          /* in: first record to copy */
    dict_index_t *index, /* in: record descriptor */
    mtr_t *mtr);         /* in: mtr */
/***************************************************************
Deletes a record at the page cursor. The cursor is moved to the
next record after the deleted one. */

void page_cur_delete_rec(
    /*================*/
    page_cur_t *cursor,   /* in: a page cursor */
    dict_index_t *index,  /* in: record descriptor */
    const ulint *offsets, /* in: rec_get_offsets(cursor->rec, index) */
    mtr_t *mtr);          /* in: mini-transaction handle */
/********************************************************************
Searches the right position for a page cursor. */
UNIV_INLINE
ulint page_cur_search(
    /*============*/
    /* out: number of matched fields on the left */
    page_t *page,        /* in: index page */
    dict_index_t *index, /* in: record descriptor */
    dtuple_t *tuple,     /* in: data tuple */
    ulint mode,          /* in: PAGE_CUR_L, PAGE_CUR_LE, PAGE_CUR_G,
                         or PAGE_CUR_GE */
    page_cur_t *cursor); /* out: page cursor */
/********************************************************************
Searches the right position for a page cursor. */

void page_cur_search_with_match(
    /*=======================*/
    page_t *page,        /* in: index page */
    dict_index_t *index, /* in: record descriptor */
    dtuple_t *tuple,     /* in: data tuple */
    ulint mode,          /* in: PAGE_CUR_L, PAGE_CUR_LE, PAGE_CUR_G,
                         or PAGE_CUR_GE */
    ulint *iup_matched_fields,
    /* in/out: already matched fields in upper
    limit record */
    ulint *iup_matched_bytes,
    /* in/out: already matched bytes in a field
    not yet completely matched */
    ulint *ilow_matched_fields,
    /* in/out: already matched fields in lower
    limit record */
    ulint *ilow_matched_bytes,
    /* in/out: already matched bytes in a field
    not yet completely matched */
    page_cur_t *cursor); /* out: page cursor */
/***************************************************************
Positions a page cursor on a randomly chosen user record on a page. If there
are no user records, sets the cursor on the infimum record. */

void page_cur_open_on_rnd_user_rec(
    /*==========================*/
    page_t *page,        /* in: page */
    page_cur_t *cursor); /* in/out: page cursor */
/***************************************************************
Parses a log record of a record insert on a page. */

byte *page_cur_parse_insert_rec(
    /*======================*/
    /* out: end of log record or NULL */
    ibool is_short,      /* in: TRUE if short inserts */
    byte *ptr,           /* in: buffer */
    byte *end_ptr,       /* in: buffer end */
    dict_index_t *index, /* in: record descriptor */
    page_t *page,        /* in: page or NULL */
    mtr_t *mtr);         /* in: mtr or NULL */
/**************************************************************
Parses a log record of copying a record list end to a new created page. */

byte *page_parse_copy_rec_list_to_created_page(
    /*=====================================*/
    /* out: end of log record or NULL */
    byte *ptr,           /* in: buffer */
    byte *end_ptr,       /* in: buffer end */
    dict_index_t *index, /* in: record descriptor */
    page_t *page,        /* in: page or NULL */
    mtr_t *mtr);         /* in: mtr or NULL */
/***************************************************************
Parses log record of a record delete on a page. */

byte *page_cur_parse_delete_rec(
    /*======================*/
    /* out: pointer to record end or NULL */
    byte *ptr,           /* in: buffer */
    byte *end_ptr,       /* in: buffer end */
    dict_index_t *index, /* in: record descriptor */
    page_t *page,        /* in: page or NULL */
    mtr_t *mtr);         /* in: mtr or NULL */

/* Index page cursor */

struct page_cur_struct
{
  byte *rec; /* pointer to a record on page */
};

#ifndef UNIV_NONINL
#include "page0cur.ic"
#endif

#endif
